drm/amd/display: Add SPL namespace

[Why]
In order to avoid component conflicts, spl namespace is needed.

[How]
Adding SPL namespace to the public API os that each user of SPL can have
their own namespace.

Signed-off-by: Navid Assadian <Navid.Assadian@amd.com>
Reviewed-by: Samson Tam <Samson.Tam@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/sspl/dc_spl.c

@@ -1819,7 +1819,7 @@ static bool spl_calculate_number_of_taps(struct spl_in *spl_in, struct spl_scrat
 }
 
 /* Calculate scaler parameters */
-bool spl_calculate_scaler_params(struct spl_in *spl_in, struct spl_out *spl_out)
+bool SPL_NAMESPACE(spl_calculate_scaler_params(struct spl_in *spl_in, struct spl_out *spl_out))
 {
 	bool res = false;
 	bool enable_easf_v = false;
@@ -1884,7 +1884,7 @@ bool spl_calculate_scaler_params(struct spl_in *spl_in, struct spl_out *spl_out)
 }
 
 /* External interface to get number of taps only */
-bool spl_get_number_of_taps(struct spl_in *spl_in, struct spl_out *spl_out)
+bool SPL_NAMESPACE(spl_get_number_of_taps(struct spl_in *spl_in, struct spl_out *spl_out))
 {
 	bool res = false;
 	bool enable_easf_v = false;

drivers/gpu/drm/amd/display/dc/sspl/dc_spl.h

@@ -9,10 +9,22 @@
 #define BLACK_OFFSET_RGB_Y 0x0
 #define BLACK_OFFSET_CBCR  0x8000
 
+#ifndef SPL_PFX_
+#define SPL_PFX_
+#endif
+
+#define SPL_EXPAND2(a, b)         a##b
+#define SPL_EXPAND(a, b)          SPL_EXPAND2(a, b)
+#define SPL_NAMESPACE(symbol)     SPL_EXPAND(SPL_PFX_, symbol)
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* SPL interfaces */
 
-bool spl_calculate_scaler_params(struct spl_in *spl_in, struct spl_out *spl_out);
+bool SPL_NAMESPACE(spl_calculate_scaler_params(struct spl_in *spl_in, struct spl_out *spl_out));
 
-bool spl_get_number_of_taps(struct spl_in *spl_in, struct spl_out *spl_out);
+bool SPL_NAMESPACE(spl_get_number_of_taps(struct spl_in *spl_in, struct spl_out *spl_out));
 
 #endif /* __DC_SPL_H__ */